In systems provided with this type of functional circuit or circuits, implementation of various kinds of operating modes or applications is made possible by changing programs or set value (called program data hereinbelow) loaded into functional circuits.
This type of conventional system is adapted to pre-store (prepare program data) of various types or many sets thereof in memory, and, in response to a requested application, the microprocessor reads out a set of program data from the memory and loads the program data into functional circuits. For this reason, the microprocessor needs to hold the storage addresses for all the sets of program data in memory in advance.
When, however, changes concerning the data length of the program data stored in memory occur due to system version upgrades and the like, the addresses or storage locations of program data sets stored in memory are inevitably changed. In such a case, software must be corrected in accordance with such changes concerning program data storage addresses on the microprocessor side, which is extremely burdensome.
Also, in the system in which the above-mentioned microprocessor reads out program data from memory and stores it into functional circuits, the microprocessor itself carries out processing while successively reading out and decoding the control program from memory, which is the reason this is time-consuming and it is difficult to carry out program storage quickly. Therefore, this was not intended for systems that must operate immediately after turning it on or after a mode change.
The present invention solves the problems of the prior art and one object of the invention is to provide a program loading method and apparatus adapted to carry out loading processing of program data without the need for changes in the software even if changes in storage addresses or data length of the program data stored in the program memory do take place.
Also, another object of the present invention is to provide a program loading method and apparatus adapted to carry out loading processing of program data at high speed and efficiency.